Exhaled air collecting vessel

ABSTRACT

Improved sampling of air in a device for collecting exhaled air, for example in the analysis of gases exhaled by a person under examination. The gas is collected in a chamber defined by an inner container with perforated walls surrounded by an outer inflatable bag, and this invention provides improved sampling by extracting air from the chamber through an extension having a number of spaced apart air entry apertures leading into said chamber.

[ Dec. 11, 1973 United States Patent [1 1 Jaeger EXHALED AIR COLLECTING VESSEL Primary Examiner-S. Clement Swisher Attorney-Edwin E. Greigg y Mn a u um. km

r EW n I M 7 [22] Filed: Apr. 7, 1972 ABSTRACT [21] Appl. No.: 241,989

roved sampling of air in a device for collectin haled air, for example in the analysis 0 d in a chamber defined by an inner container with perforated walls surrounded by an outer inflatable bag, and this invention provides improved sampling by extracting air from the chamber through an extension Imp g exf gases exhaled by a person under examination. The gas is collecte having a number of spaced apart air entry apertures leading into said chamber.

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M U IF [56] References Cited UNITED STATES PATENTS 6 Claims, 1 Drawing Figure 3,661,528 5/1972 Falk 73/4215 R H VIIIIII 1 g 4, l 6

1 EXHALED AIR COLLECTING VESSEL BACKGROUND OF THE INVENTION The present invention relates to an exhaled air collecting device for use in the measurement of variations in the quantity of exhaled gaseous material exhaled by a person under examination.

It is known for such an exhaled air collecting device to comprise an inner container having an inlet for the exhaled air, an outlet leading to the atmosphere, and at least one opening in the container wall leading to an easily inflatable bag which, together with the interior of the inner container, forms a collecting chamber for the exhaled air, and an air extraction pipe.

Such a collecting device for exhaled air is described in German Gebrauchsmuster Specification 1,193,629 and the corresponding German Patent Specification No. 1,616,010.

For some time there have been available rapid response gas analysis instruments for oxygen and carbon dioxide. When using known types of exhalation collecting devices with such rapid response gas analysis instruments it has been'shown that the intermixing of the exhaled air, which in the known devices is extracted by a simple air extraction pipe projecting into the extraction device, is insufficient. In particular in the case where the person under examination is subjected to high physical stress with consequential severe surges in the amount of air being inhaled and exhaled, there will be undesirably intense fluctuations in the concentration of the measured gas.

An object of the present invention is to avoid this disadvantage by providing a collecting device for exhaled air in which the composition of the air extracted through the air extraction pipe corresponds better with the average composition of the air contained in a collecting chamber of the exhaled air collecting device.

SUMMARY OF THE INVENTION According to the present improvement there is provided an exhaled air collecting device for use in measuring variations in the quantity of gaseous material exhaled by a person under examination, said collecting device comprising an inner container having an inlet for exhaled air, an outlet leading to the atmosphere and at least one opening in the container wall leading to an easily inflatable bag which, together with the interior of the inner container, forms a collecting chamber for the exhaled air, and an air extraction pipe having an extension leading into the said exhaled air collecting chamber, the extension being provided with a plurality of mutually spaced apart air entry apertures.

By means of the air entry apertures, the air is extracted from a plurality of different regions of the collecting chamber and satisfactory mixing is thereby achieved.

Preferably the extension comprises a tube, the wall of which is provided with a number of said air entry apertures distributed in the longitudinal direction of the tube. Such an extension may be manufactured easily and inexpensively, and existing collecting devices can i be easily converted.

this means it can be ensured that at least approximately equal quantities of air can be extracted from different regions along the length of the extension.

Preferably that portion of the extension which is provided with the air entry apertures is situated outside the inner container. The said portion of the extension may, for example, extend along the outside of the inner container and substantially parallel to the longitudinal axis thereof.

. DESCRIPTION OF THE DRAWING An exhaled air collecting device according to a practical embodiment of the invention will now be described, merely by way of example, with reference to the accompanying Drawing, which is a diagrammatic sectional elevation of the device.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The exhaled air collecting device shown in the drawing comprises an inner container lin the form of a flask made of synthetic plastics material having a relatively wide opening 2 at one end covered by a wire mesh 3. The wire mesh 3 is secured to the said end of the inner container 1 by means of an annular flange 4 secured to the said end of the container 1 and surrounding the opening 2. The flange 4 has an external annular groove 5 which receives an elastic retaining ring 6. The container 1 has a neck 8 at its other end which serves as an inlet for exhaled air. When the device is in use the neck 8 is connected to a tube (not'shown). into which the person under examination breathes through a mouthpiece or a breathing mask.

The inner container 1 has a cylindrical side wall provided with axially elongated slot shaped openings 9 spaced around its circumference. In the region of the neck 8 an air extraction pipe 10 is fitted to the inner container 1. At the end of the side wall of the inner container 1 adjacent the neck 8 the container side wall isprovided with an external annular depression 11 in 14. In the illustrated example the tube 14 passes through a hole in the side wall of the inner container 1 and then extends parallel to the direction of the axis 15 of the container 1 along the external wall of the latter, to which it is secured in a suitable: manner, for example by cementing, welding or by means of retaining clips (not shown).

The extension tube 14 may, for example, have an internal diameter of about 5 mm, and its wall is provided in its axially extending portion with a row of air entry apertures 16 which are distributed along the length of the tube 14 and which may also be distributed around the circumference of the tube 14. The size of the apertures 16 preferably increases with increasing distance from the extraction pipe 10 towards an upper end 17 of the tube 14, which may be open or closed, so that approximately the same quantity of air is extracted by the tube 14 from all regions of the exhaled air collecting chamber defined by the interior of the inner container 1 and the bag 13.

The extension tube 14 need not extend outside the inner container 1 but it may consist, for example, of a rigid tube which projects into the interior of the inner container 1. However the arrangement of the extension tube 14 shown in the drawing has proved to be particularly satisfactory and effective in practice.

What is claimed is:

1. An exhaled air collecting device for use in measuring variations in the quantity of gaseous material exhaled by a person under examination, said collecting device comprising:

an inner container having a container wall, an inlet for exhaled air and an outlet leading to the atmosphere;

means defining at least one opening in said container wall; an easily inflatable bag surrounding said container wall and, together with the interior of the inner container, defining a collecting chamber for the exhaled air;

an air extraction pipe connected to said chamber,

and

the improvement which consists in extension means leading into said exhaled air collecting chamber, said extension means being provided with a plurality of mutually spaced apart air entry apertures.

2. The collecting device claimed in claim 1, wherein said extension means comprises a tube having a wall which is provided with a number of said air entry apertures distributed in the longitudinal direction of the tube.

3. The collecting device claimed in claim 1, wherein said air entry apertures have different sizes.

4. The collecting device claimed in claim 3, wherein the size of said air entry apertures increases in a direction towards the end of said extension means remote from said extraction pipe.

5. The collecting device claimed in claim 1, wherein the portion of the extension means which is provided with the air entry apertures is situated outside said inner container.

6. The collecting device claimed in claim 5, wherein the said apertured portion of the extension means is secured to the outside of the inner container and extends substantially parallel to the longitudinal axis of said inner container. 

1. An exhaled air collecting device for use in measuring variations in the quantity of gaseous material exhaled by a person under examination, said collecting device Comprising: an inner container having a container wall, an inlet for exhaled air and an outlet leading to the atmosphere; means defining at least one opening in said container wall; an easily inflatable bag surrounding said container wall and, together with the interior of the inner container, defining a collecting chamber for the exhaled air; an air extraction pipe connected to said chamber, and the improvement which consists in extension means leading into said exhaled air collecting chamber, said extension means being provided with a plurality of mutually spaced apart air entry apertures.
 2. The collecting device claimed in claim 1, wherein said extension means comprises a tube having a wall which is provided with a number of said air entry apertures distributed in the longitudinal direction of the tube.
 3. The collecting device claimed in claim 1, wherein said air entry apertures have different sizes.
 4. The collecting device claimed in claim 3, wherein the size of said air entry apertures increases in a direction towards the end of said extension means remote from said extraction pipe.
 5. The collecting device claimed in claim 1, wherein the portion of the extension means which is provided with the air entry apertures is situated outside said inner container.
 6. The collecting device claimed in claim 5, wherein the said apertured portion of the extension means is secured to the outside of the inner container and extends substantially parallel to the longitudinal axis of said inner container. 